Filter medium comprising metal fibers are known in the art. As an example, WO03/047720 discloses a multilayered sintered metal fiber filter medium for filtration of diesel soot from exhaust gas of a diesel combustion engine. Although performing satisfactorily, this medium may have the disadvantage that only limited amount of soot can be held before the medium gets clogged. As a result, very frequent and numerous regeneration actions need to take place, e.g. by regeneration using electrical regeneration (i.e. conducting electrical current through the medium, causing a heating of the medium due to the Joule effect) or regeneration by injection of catalytic compounds in the diesel or exhaust gas. Other disadvantages are that this medium is limited in efficiency and is rather expensive.
An alternative, multilayered filter medium suitable for filtering diesel exhaust gasses of a diesel combustion device such as a diesel combustion engine, is described in WO04/104386. This medium has, due to its substantially larger thickness, an increased soot holding capacity. The medium has the disadvantage that in order to reach this increased soot holding capacity, large volumes are needed and relative high pressure drops over the filter medium may be obtained, also in case of fresh, i.e. unused, filter media. The large amounts of soot may however be disadvantageous in case other exhaust cleaning elements are used downstream the filter media, e.g. elements reducing NOx to NO2 by means of SCR-processes. During regeneration, the large amounts of soot is ignited and during oxidation, a too large temperature may be provided to the exhaust gasses passing the filter media and hence the SCR-process during regeneration. These high temperatures may negatively influence the working of the SCR-processes.